Localbitcoins.com , you’ll find a number of Bitcoin merchants here in Kenya with different payment options that they accept, from MPESA, Equitel and even Airtel Money.
Different merchants also have different minimum and maximum amounts that they accept per transaction, as well as different ratings. I advice you go for the ones rated 100% ratings
The site is also a Bitcoin wallet, but I prefer u have another wallet like Bitwala, Coinbase or Luno.
Bitpesa is also another alternative to localbitcoins, however, they have a minimum transaction amount of 70,000

i have used local bitcoins to buy and sell bitcoins locally,i dont know about the other cryptocurrencies…Well,currently i am not pursuing cryptocurrencies coz of the volatility and it seems very speculative at the moment,hasnt gone fully mainstream…Anyway,you can invest if you have money to burn/lose otherwise now is not a good time to buy into it.

The one i transacted with used the username “scorpius” but I really can’t recommend any specific buyer/seller., go for the ones rated 100%, they are the ones with whom you are sure to get your Bitcoins or cash

If the PC does not have a high end dedicated GPU, I wouldn’t bother. The return will be so low.

If you decide to go ahead and do it, I’d suggest you avoid mining bitcoin and pick a different crypto. Nicehash’s mining software will help you pick the best crypto to mine based on your configuration.

All said and done, you should be profitable since you have no initial or recurring costs.

Internet should not be an issue. You can even use your mobile plan to mine.